Battlestar Galactica (2003) to Buffy the Vampire Slayer
3 connections
Battlestar Galactica (2003)
Firefly
Battlestar Galactica's pilot had a scene showing a Firefly class ship flying over
Angel
Weyland-Utani is a client of Angel's Wolfram & Hart and also the company that made some of the weapons used by Firefly's Malcolm Reynolds in the Battle of Serenity
Buffy the Vampire Slayer
Angel was a spin-off of Buffy the Vampire Slayer.